Nominal vs Peak what is the difference?
Nominal power output refers to the rated power that a motor can produce without damaging itself.
Peak output is the maximum power that a motor can generate for short periods of time before overheating or other issues can occur. That being said the controller is constantly calculating the speed, velocity and torque demand, and with that, the output is calculated. As a result, the motor may reach peaks for an extremely short time (sometimes a fraction of a second to 1 or 2 seconds).
So why not run at Peak Wattage for a longer period?
Well, that would mean the coils would get too hot and then would need more time to cool down, which in turn would result in less than the nominal power output delivery for the next few minutes or till the coils cool down to a safe operating level.
So why mention the Peak Wattage at all?
That is because it is an industry standard for DC motors on eBikes to list their peak wattages along with their Nominal Wattage rating. Some DIY customers/ project developers need this information to design their own solutions for advanced-level operations.